Various drugs have heretofore been known to exhibit organ preserving or protecting actions [see, for example, Japanese Patent Domestic Announcement (kohyo) No. 502819/1986, Japanese Patent Public Disclosure (kokai) Nos. 267233/1987, 20/1989, 72432/1991, 101621/1991 and 43463/1993.
In particular, Japanese Patent Public Disclosure (kokai) No. 101621/1991 teaches that N-(2-hydroxyethyl)nicotinamide nitrate ester (generic name: nicorandil) having a hydroxy radical scavenging action is applicable as an organic preservative and protective.
Nicaraven has been known to be useful as a thrombolytic agent, anti-arteriosclerotic agent and as an anti-cerebral vasospasm agent [see Japanese Patent Publication (kokoku) No. 55911/1986] but there have been no reports that this compound exhibits an organ preserving or protecting action.
The various drugs heretofore known to have organ preserving or protecting actions are not completely satisfactory in their operational activity. Even with drugs that are by and large potent in their operational activity, problems are often encountered in such aspects as the side-effect and safety features of the drugs per se. Hence, very few have been commercialized as practical medicines.